Bought half of new build, rest unsure of

[Appledrop]

hey so I haven't built a PC in ages so I have a few questions, but went ahead and bought the following bits today:

monitor=HP LP2475w 24" ips
case=Silverstone TJ09B Black Aluminium
psu=1250W CoolerMaster Real Power Pro (think i made a mistake here, maybe not modular)
gpu (1?) = gainward gtx 295
cpu cooler=coolit domino watercooling unit (anyone have this? do you need thermal paste still? If so ill have to grab some)
hdd=1tb hitatchi deskstar sataii (was on offer.. are these still known as "death stars?")
mouse=logitech g9
kb= razer lycosa mirror

my questions are:
is i7 920 the only logical cpu here? any differences other than clockspeed (i will be OCing)?
if so thats sorted
but
i'd like decent mobo with SLI and maybe with dedicated onboard sound - i used to have an x-fi xtreme music pci that I liked, before it was stolen, so.. otherwise no big deal, can buy PCI

also what ram? I guess 6gb, having looked around. Does i7 platform have memory dividers that dont hinder performance? Or does memory bandwidth make a difference these days.. Ie is pc 15000 ram a gimmick or will it help much?|

another thing, if I can afford it, should I shoot for 2x gtx 295 sli or does the added heat, noise, power, and cost make it not worth it?

finally, anyone have logitech g9? what mousepad would you recommend

thanks guys, mm long post probably tl;dr :<

 

[theAnimal]

One GTX295 is plenty for a 19x12 resolution, which makes your PSU extreme overkill and it will be inefficient due to the relatively low power draw. I would recommend the Corsair HX750 instead.

Definitely i7 920 and for the mobo Gigabyte, ASUS are good choices. And OCZ Platinum 1600 3x2GB for the RAM.